Perforator



H U. BAKER' PERFORATOR Jan. 5, lg32.

Filed' May 20. 1929 Patented Jan. 5, 1932 UNITED STATES PATENT OFFICE LD 'U'. BAKER, OF LOS ANGELES, CALIFORNIA, ASSIGNOR 0F THREE-EIGENE T0 ELMORE D. JONES, OF LONG BEACH, CALIFORNIA, AND THREE-EIGHTHS TO WIN- FIELD S. JONES, OF BREA, CALIFORNIA PEBFORATOB Apfueaaon mea my zo, 192s. serial No. 364,420.

This invention contemplates an improvement upon the invention of Winield S. Jones and the present inventor for perforators, patented in the United States September 25, 1928, No. 1,685,492. In said patent, we described a perforator having cer'tain novel features whereby a cutter blade was released when the perforator was positioned at 'a des'ired point within the casing, and which cutter blade was adapted to perforate the said casing when so positioned. rl"he present inventlon contemplates a perforator so arranged and constructed as to allow the ready perforation of casing at any zone desired and with minimum effort. With respect to the above, when a well hole is of great depth, a turning of the stem carrying the cutter tends to cork screw the said stem, particularly when pressure is exerted downwardly upon the stem. This motion is analogous to stretching a thin wire across a. room and then attempting to push upon the wire so as to force some object through another object at the opposite endof the wire. This might be accomplished but could only be accompllshed with difliculty and the same is true when pressure is exerted upon a stem in a. well hole vso as to force a cutter through casing many thousand feet from the surface of the well hole.

The present invention has for an object a novel means whereby cutters may be forced through the casing without fear of endangering the stem.

Other objects of the invention include a device which is simple of construction, easy to operate, little fear of injuring the cutting tool or damaging the stem, and which is generally superior in use and serviceability. .With the above mentioned and other` ob- ]ects in view, the invention consists i the novel and useful provision, formation, construction, association andrelative arrangement of parts, members and features, all as shown in a certain embodiment in the accompanying drawings, described generally, and more particularly pointed out in the claims. V n

In the drawings:

Aline 4-4 of Figure 2.

Referring to the drawings, in order to properly describe this cutter, certain of the notations and description glven in Patent i No. 1,685,492 .will again be included, although for fuller explanation, reference 1s had to said patent.

Referring with particularity to the drawi ings the improved perforator is designated as an entirety by A, and the same includes a body a, a member b movable relative to the body, gripping means c and d, a cutter e, and means f for actuating the cutter, all of which elements are used in practicing one embodiment of the present invention. The body. a is formed at one end with a circular chamber or bore 1, and likewise provided with screw-threads 2. Adapted to be received in part within said -bore 1 is a mandrel 3 constituting a part of the actuating means f for the cutter e. This plunger is vformed with a head 4 and a stem or arm 5,

the stem or arm 5 bein substantially circular, and passed throug a guide bushing 6 in threaded. engagement with the threads 2. The cutter e is arcuate or curved and adapted to be fitted within a curved bore 7 which communicates with the bore 1 and externally of the body a, as shown at 8. The cutter blade is secured to the mandrel by means of a link 9, which link is pivoted respectively to the mandrel head 4 and an end of the cutter blade as indicated at 11 and 10. The cutter blade is formed with a substantially sharp or pointed object-engaging nose 12. Thus, 1f the mandrelwas allowed movement, the cutter blade would reciprocate within the curved which constitutes inreality a sleeve is movf able upon such reduced end. The said sleeve is provided with a base portion 14 having a central bore 15. The body a at the reduced end portion is recessed at 16 to in part confine a latch 17 pivoted to said body at 18 and the said latch has a notched end 19. The member b is slotted at 20 so that the said latch may when in one position, as shown in Figure 2a, engage an end wall 21 bounding said slot 20. The body a is formed to carry one'or more of the slips d, and the body to this end is formed with a plane surface 22 which is at an angle to the outer surface of the body. This construction forms a ledge 23. A bore 24 is passed through the body at the ledge portion 23 and adJacent the portion of reduced diameter of said body. The slip d is substantially wedge-shaped and is adapted to be substantially flush with the outer surface of the body when the same is itted against the inclined wall 22, as shown in the res. An arm 26 is passed through said ore 24, and connected to the slip d. The opposite end of said arm is secured to the sleeve 7J, by providing said arm with an angular extremity 27 received in a transverse bore 28 of the sleeve. Ada ted lto be fitted within the member b and li ewise slidable therein, is a head 29, and joined with Isaid head is a mandrel 30, the shank# portion of which is passed through the bore 15 in the base of the sleeve. Carried on this mandrel and slidable thereon is the friction spring member c which includes two spring arms 31 and 32 whichare secured to top and bottom collars 33 and 34, which collars are carried on the mandrel. The said member y c is prevented from escape from the mandrel inl any' suitable manner, such as by a nut 35 screw-threaded upon an end ofthe mandrel. To maintain the various parts in association, as shown in Figure 2a, a frangible in 36 is passed through the stem 3, and which pin will bear against the top surface of the nut 6 secured to the body, and thus hold the plun r elevated and maintain the cutter within the bore 7 of the body. Likewise a frangible pin is passed through aligned bores 37 in the sleeve b and the head 29, whereby the mandrel is maintained in a certain position relative to said sleeve. The position is likewise such that the latch 17 is held so that the notch 19 bears against the head 29. The latch is kept in tight engagement with the head and likewise the sleeve through the .medium of a leaf spring 39 secured to the reduced portion of the body and bearing against the top edge of the said latch, as shown at 40.

More particularly, the present invention is directed to suitable means for boosting or increasing the pressure of the cutter against the casing. As was pointed out in the objects, ofttimes the mere weight of the stem due totwist and the like thereof is insuf`- cient toforce the cutter through a casing, or the stem in damaged in the attempt to force the cutter through the casing. The present invention, by boosting the relative downward pressure permits the cutter to be operated without damage to the stem. This particular means' is desi ated as f and the same includes that portlon of the device shown in Figure 2 and above the bushing 6. 'The mandrel 3 is passed through the bushing 6 and carries at its upper end a iston head 41. This piston head includes a su stantially cir- 'cular piece mounted upon the mandrel and provided with two portions of reduced diameter 42 and 43, all portions being arranged concentrically. The portion l 43 is screwthreaded at 44. This piston head is within an elongated cylinder 45, one end of which cylinder is screw-threaded to the bushing 6, as shown at 46. Surrounding the portion 42 of the piston head is a packlng member 47 and screw-threaded to the threads 44 of the portion 43 of the piston head is a sleeve 48. The end of the sleeve where it is screwthreaded to the part 43 is adapted to bear against a washer 49 which in turn bears against the packing piece to hold the same in position on the piston head 41. This sleeve 48 is confined within the cylinder 45 and said sleeve is transversely and diametrically slotted, as shown at 50. Furthermore, the periphery of the sleeve is slightly spaced from the inner wall of the cylinder. The upper end of said cylinder is screw-threaded to a bushing 51, which bushing in turn is screw-threaded to a tubular member 52. Adapted to be passed through the tubular member 52, bushing 51 and intoA the sleeve 50 is a plunger 53. A member 54 is passed transversely through the plunger `at 55 and is received within the transverse slot of the sleeve 50. This plunger is provided with an annular flange 56, which flange is slightly less in diameter than the inner diameter of the tubular member 52. The 'tubular member 52 is adapted to have screw-threaded at the upper end thereof a cap nut 57. Likewise said tubular member is provided with an internal annular fiange 58' near the opposite end of said tubular member. The bushing 51 is provided with a port 59 which will allow communication externally of the bushing and internally of the cylinder 45. The bushing 6 is provided with ports 60 and 61 which in. ter-communicate and likewise permit communication within the cylinder`45 and the bore 1 of the cutter body a.

The bushing 51 is likewise centrally bored to house a packing-and gland 62 and 63 respectively. The plunger 53 exteriorly of the tubular member communicates with the drill stem 64.

The operation, uses and advantages of the invention just described are as follows:

If it is desired to perforate the casing and assuming that the slips are engaging the casing to hold the body in a given position so that the cutter may be urged outwardly from the body for casing engagement, then said cutter would be actuated as follows:

Downward movement of the stem 64 will -cause downward movement of the plunger .mandrel 3 which will, of course, cause movement of the cutter. The cross sectional area of the head of the plunger acting within the slotted sleeve is considerably less than the cross sectional area of the -top of the piston head 41 and thus a differential pressure and stroke is the result. The openin s in the bushing`permit ready escape o any oil back of the piston head into the bore l, and thus back pressure is overcome. When it is desired to retract the cutter, the stem may be moved upwardly which-will in turn move theplunger upwardly. The member 54 will carry the sleeve when it contacts with the head of said sleeve and elevate the sleeve, it being remembered that this sleeve is secured to the piston head and, of course, upward movement of the piston head would raise the mandrel connected with the cutter. Movement of the lunger is arrested when the flange 56 stri es the cap on the end of the tubular member 52. This form of device is ver efiicient in operation and lassures that un ue strain on the working parts of the device is effectively prevented. It is possible to position the perforator anywhere desired within the casing and then, with less ressure than would be ordinarily required il) the differential or booster system is not utilized, cause saidcutter to pierce the casmg:

It is to be particularly noted that the sleeve does not fit tightly within the cylinder 'nor does the plun er iit tightly within the sleeve. Thus, when ne plunger moves downwardly withintthe sleeve, the fluid within said cylinder and sleeve is forced downwardly and likewise permitted to flow upwardly around the plunger and likewise into the space included between the sleeve and the inner wall of the cylinder.

. For 'further of this type, reference is again directed to the patent `heretofore mentioned.

It is obvious that various changes and modifications and variations may be made in' practicing the invention in departure from the partcular showing of the drawings and description as given without, however, de-

parting from the true spirit of the invention.

details concerning a cutter4 I claim:

l. A perforator adapted to be placed within a casing including a body, a cutter carried thereby, and differential pressure means for actuating said cutter.

2. In a perforator adapted to beplaced within a casing, a body, a cutter carried thereby, a piston for said cutter, and means for creating a diferentialpressure against said iston to actuate said cutter.

3. a de 'ce of the character disclosed, a cutter blade, a piston head connected thereto, a cylinder for said piston head, and a plunger having a lesser cross sectional area than the cross sectional area of the piston head, said plunger being movable within said cylinder, and fluid means within the cylinder whereby differential pressure between the plunger and the piston head results when the plunger ismoved to compress said fiuid.

4. In a device of the character disclosed, a cutter blade, a piston head connected thereto, a cylinder for said piston head, a plunger having a lesser cross sectional area than the cross sectional area of the piston head, said plunger being movable within said cylinder, and fiuid means within the cylinder whereby differential pressure between the plunger and the piston head results when the plunger is moved to compress said fiuid, in combination with means for limiting movement of said plunger in two directions.

5. n a perforator, a cylinder, a piston head therein, a slotted sleeve within said cylinder and secured to said piston head, a plunger within said sleeve, said cylinder being adapted to confine a fluid, and whereby movement of the plunger within the sleeve creates a differential pressure against said piston.

6. In a perforator, a cylinder, a piston head therein, a slotted sleeve within said cylinder and secured to said piston head, a

lunger within said sleeve said cylinder belng adapted to confine a iuid, and whereby movement of the plunger within the sleeve creates a differential pressure against said piston, in combination with means for limiting movement of said plunger within said sleeve.

7. -In` a perforator, a cylinder, a piston head therein, a slotted sleeve within said cylinder and secured to said piston head, a plunger vwithin said sleeve, said cylinder being adapted to confine a fluid, and whereby movement of the plunger within the sleeve creates a differential pressure against said piston, in combination with a cutter joined with said piston head for guiding movement of said cutter when the piston head is moved.

8. In a device of the character disclosed, a cutter blade, a piston head connected thereto,'a cylinder for said piston head, and a plunger having a lesser cross-sectional area thar the cross-sectional area of the piston hea 4 mammie` 9. In a device of the character disclosed, a cutter blade, a piston head connected thereto, a cylinder forsaid piston heed, and e plunger having a lesser cross-sectional area, than the cross-sectional area of the piston head, said cylinder being adapted to house a fluid and whereby when the plunger is moved within said cylinder, a diierential ressure between the plunger and piston vhea results. In testimony whereof, I have signed my name to this specification at Los Angeles, California, this 25th day of January, 1929. HAROLD U. BAKER. 

